This invention relates to a medical implant device for electrostimulation and/or electrical monitoring of endo-abdominal tissue or viscera. More specifically, this invention provides a medical implant device having electrode leads which can be attached or affixed to the enteric or endo-abdominal tissue or viscera such that the electrode leads resist detachment in spite of the vigorous and/or periodic action or movement of the enteric or endo-abdominal tissue or viscera. The medical implant device of this invention is especially adapted for location or implantation in the endo-abdominal cavity over extended periods of time.
It is well known that more than 70% of illnesses affecting the digestive tract are of a functional nature. Today such illnesses are treated predominantly using pharmacological means. Since drugs generally have side effects, particularly when the drugs cure the symptom and not the underlying problem or dysfunction, they must often be administered temporally. Indeed, if the side effects are sufficiently serious, the drug may have to be discontinued before full benefit to the patient is realized; in many cases the underlying illness remains.
The important role played by electrophysiology in controlling gastrointestinal activity has become increasingly apparent in recent years. Thus, the possibility exits of correcting dysfunction by means of electrostimulation applied at specific frequencies, sites, and modalities and with regard to the self-regulating electromotor physiology of the gastrointestinal organs or tract. It has recently been shown, for example, that changes occur in the motility and electromotor conduct of the gastric tract in eating disorders (e.g., obesity, thinness, bulimia, anorexia). Disturbances in electromotor activity in diabetic gastroparesis, reflux in the upper digestive tract, and numerous other gastroenterological functional pathologies have also been observed.
Stimulation of the intrinsic nervous system of the stomach is likely to have two major consequences or effects: (1) the correction and direct control of the electromotor activity of the intestines and (2) the stimulation of increased incretion of specific substances (i.e., gastroenteric neuromediators) produced by the intrinsic nervous system itself through the myenteric plexus. Curing of functional illnesses involving the digestive system and, more broadly, involving disorders in any way connected to, or associated with, the digestive system is, therefore, closely linked to the progress of research in the field of electrophysiology.
An indispensable condition for modifying the electrical activity of the digestive system""s intestinal tract and related neurohormonal incretions is the use of an implant system to generate electrical impulses (electrical stimuli) and means (e.g., electrocatheters) to connect them to the viscera and/or intestines to be stimulated. These treatment methods involve an xe2x80x9cinvasivexe2x80x9d surgical technique to implant the electrocatheter in the abdomen. This may involve open or, preferably, micro-invasive surgery (i.e., video-laparoscopic surgery). Current electrocatheters to stimulate electrically and/or monitor endo-abdominal viscera normally have metal microbarbs which are angled in such a way as to permit application of the end of the catheter and to prevent it subsequently from being dislodged. However, this type of catheter is often very complicated to make and, consequently, is very costly. Moreover, metal microbarbs can damage surrounding tissue especially when exposed to the vigorous action of the digestive tissue and/or organs. Among the undesirable consequences of such damage is evasion of the electrode into the lumen of the gastrointestinal tract. This would result in contamination of the abdominal cavity and the electrode. The subsequent infection would, at a minimum, require removal of the catheter and involve an additional operation.
During laparoscopic procedures, after administering a general anesthetic, the patient""s abdomen is inflated with CO2 or another inert inflammable gas, thereby transforming the abdominal cavity from a virtual to a real cavity. Rigid tubes with air-tight valve mechanisms (xe2x80x9ctrocarsxe2x80x9d) are then inserted into the gas-filled abdominal cavity so that a video camera and other surgical instruments can be introduced into the abdomen. The operation then proceeds by viewing the video images transmitted by the camera. Multiple trocars are required. Generally, the first trocar provides access to the abdomen by the video camera in order to monitor the surgical procedure. A clamp is normally inserted in the second trocar to move or retain the hepatic edge that normally covers the lesser curve of the stomach or other viscera depending on the type of operation to be performed. A third trocar provides access for a maneuvering clamp or laparoscopic forceps. The fourth trocar is used for the introduction of instruments as well as the electrocatheter to be implanted in the stomach wall of the patient. The structure of the electrocatheter plays an important part in facilitating the specific operation for whichever of the patient""s organs and/or viscera the surgeon aims to stimulate.
Each of the trocars used, of course, requires a separate tract through the skin and abdominal wall. To keep the abdomen inflated, valves are used with the trocars to provide a gas-tight seal. Introduction of a medical device, such as an electrocatheter or implantable electrode, into the abdomen generally requires the use of laparoscopic forceps to grasp the device. Such devices, which are generally inherently fragile in nature, could be damaged if grasped too firmly by the forceps. Thus, for example in the case of an electrocatheter having electrode leads, the interior conductor wires could be broken, rendering the device dysfunctionally or completely useless.
It is, of course, desirable in laparoscopic surgery to limit the number of trocars used since each trocar requires a separate incision which results in additional visible scars for the patent. More importantly, each additional incision increases the chance of infection and other complications resulting therefrom. Therefore, to reduce the number of trocars required, implantable devices are often inserted completely through the trocar and into the abdomen so that a single trocar can serve for multiple uses (e.g., for insertion of other instruments and/or manipulation devices). Thus, the surgeon will often need to pull the distal end of the inserted device back through a trocar and/or remove the device entirely. In this case, the device needs to xe2x80x9cline upxe2x80x9d to the trocar passageway to be pulled back through the trocar. Of course, if the device is grasped by the forceps in a manner so the longitudinal dimension of the device is not alined with the trocar passageway, the device cannot be pulled back through the trocar.
It is also desirable to place the electrocatheter adjacent to the tissue or organ of interest and xe2x80x9clockxe2x80x9d it in place so that the target tissue or organ can then be electrostimulated and/or electrically monitored. As noted above, metal microbarbs have been used to lock the device in place. Such metal microbarbs can damage or tear surrounding tissuexe2x80x94especially when the implant device is subjected to the vigorous action or peristaltic movement of the digestive organs. More recently, flexible microbarbs have been used for such implant device. Although such flexible microbarbs are less likely to damage the surrounding tissue, so-equipped electrocatheters are prone to displacement when acted on by the vigorous action or movement of the digestive organs, especially when the implant device is to remain within the patient for prolonged periods of time. Additionally, the peristaltic movement may fracture the barbs, or cause erosion through the organ wall and into the lumen of the organ to which it was affixed. Once displaced, of course, the implant device can no longer provide the desired electrostimulation and/or electrical monitoring of the target tissue. Moreover, the displaced implant device may, over time, move within the body cavity to locations remote from the initial location thereby causing complications and making surgical removal more difficult. Moreover, such movement will, of course, render the implant device inoperative with regard to the initially targeted tissue and may require an additional medical procedure to retrieve and/or reposition the implant device proximal to the target tissue.
It would be desirable, therefore, to provide an improved implant device which can be easily positioned and attached or tethered to the target tissue or organ and which can then be securely locked in place. It would also be desirable to provide an improved implant device with a locking or attachment mechanism which is less likely to damage surrounding tissue, especially where the tissue is undergoing repeated and/or vigorous movement. It would also be desirable to provide an improved implant device which will resist displacement by the vigorous movement of internal organs or viscera within the abdominal or other body cavities over prolonged or extended periods of time. The present invention provides such implant devices. Although the implant devices of the present invention are especially adapted for implantation within the abdominal cavity, they can also be used throughout the body. The present implant devices can effectively xe2x80x9clock-onxe2x80x9d and resist displacement from tissue or organs which undergo repeated and/or vigorous movement. The present implant device would be especially useful, for example, within the abdominal cavity or the thoracic cavity.
This invention relates to an implant device which is designed and adapted for use in laparoscopic surgery. This implant device is especially adapted for electrostimulation and/or electrical monitoring of endo-abdominal organs, tissue, or viscera. The implant device of this invention has an elongated body having on, or near, its distal end a flexible attachment mechanism or member which can be folded back onto the elongated body and attached to the elongated body, thereby forming an essentially closed loop around or through the tissue of interest. By xe2x80x9cloopingxe2x80x9d around or through the tissue of interest, the attachment member and the elongated body are securely attached to the tissue and can resist displacement even in cases where the tissue is subject to vigorous peristaltic movement within the body (e.g., movement of the digestive organs). One preferred implant device of this invention has an elongated body equipped with at least one, and preferably two or more, electric poles that are electrically connected to an electric connection terminal for connection to a power source, a mechanism or device to penetrate the tissue or viscera to be treated, quick-release connecting devices to separate the penetration device from the elongated body, and a locking or attachment device which is capable of folding back and attaching to the elongated body whereby the locking or attachment device and the elongated body form a secure and essentially continuous loop around the tissue or viscera to be treated.
The improved implant device of the present invention is simple to handle and use, thereby simplifying the surgical procedure required to implant the device. This implant device can be easily inserted and anchored in the viscera to be stimulated without required suturing of the implant device to, or near, the tissue to be treated or requiring any maneuvers that might be difficult and risky for other viscera or for the integrity of the electrocatheter itself. This improved implant device with its attachment mechanism is especially adapted for electrostimulation and/or electrical monitoring of the tissue or viscera of the mammalian body (especially the human body), especially tissue and internal organs of the endo-abdominal cavity. Examples of such tissue and internal organs include, but are not limited to, the stomach, small intestine, large intestine, urinary bladder, gall bladder, muscles of the abdominal cavity, and tissue, muscles, and/or organs of the thoracic cavity (including, but not limited to, the cervical, thoracic and abdominal portions of the esophagus and the pharyngeal musculature in the neck), and the like. The present implant device can effectively lock onto and resist displacement from tissue or organs which undergo repeated and/or vigorous movement. Thus, the implant device of this invention are especially adapted and suitable for implantation in cases where the implant device is expected to remain for prolonged or extended periods of time.
It is one object of the present invention to provide a medical device to be used in laparoscopic surgery. Another object is to provide a medical device which allows easy insertion into the abdomen and/or removal from the abdomen through a trocar. It is another object of the invention to provide a medical device which can easily be attached to and locked on to the tissue or viscera of interest.
Still another object is to provide an implant device for attachment to internal tissue using laparoscopic surgery, said device comprising (1) an elongated body having a proximal end and a distal end and an essentially circular cross-section suitable for passage through a trocar used in laparoscopic surgery; and (2) an attachment mechanism at, or near, the distal end of the elongated body whereby the attachment mechanism can be folded back and attached to the elongated body so that the implant device is held in place and forms an essentially continuous loop around or through the tissue. Still another object of the invention is to provide an implant device specifically for electrostimulation and/or electrical monitoring of the endo-abdominal visceral tract that has significant flexibility of use since it is capable of having multiple poles and of being adapted to any surgical requirement without substantially modifying its structure.
Still another object is to provide an implant device for electrostimulation or electrical monitoring of tissue to be treated within the endo-abdominal cavity, said implant device comprising:
(1) an elongated body having a distal end and a proximal end,
(2) a penetration mechanism at the distal end of the elongated body to penetrate the tissue to be treated,
(3) a quick release connecting mechanism adjacent to the penetration mechanism which allows the penetration mechanism to be detached from the elongated body once the implant device has been properly located within the endo-abdominal cavity,
(4) an attachment mechanism adjacent and proximal to the quick release connecting mechanism, wherein the attachment mechanism, once the penetration mechanism has been detached, can be folded back and attached to the elongated body so that the implant device is held in place and forms an essentially continuous loop around or through the tissue to be treated,
(5) at least one electric pole located along the elongated body such that the electric pole is in electrical contact with the tissue to be treated when the attachment mechanism is folded back and attached to the elongated body, and
(6) an electrical connection terminal at the proximal end of the elongated body for connection to a power source, wherein the electrical connection terminal is electrically connected to the electric poles. Preferably, the elongated body has two or more electric poles.
A further object of the invention is to provide an implant device specifically for electrostimulation or electrical monitoring of tissue to be treated within the endo-abdominal cavity, said implant device comprising: (1) an elongated body having a distal end and a proximal end, (2) a penetration mechanism at the distal end to penetrate the tissue to be treated, (3) a quick release connecting mechanism adjacent to the penetration mechanism such that the penetration mechanism can be removed from the elongated body once the implant device is properly positioned relative to the tissue to be treated, (4) an attachment mechanism adjacent to the quick release connecting mechanism, such that, when the quick release connecting mechanism is activated to remove the penetration mechanism, the attachment mechanism is at or near the distal end of the elongated body and the attachment mechanism can be folded back and attached to the elongated body to form an essentially continuous loop around or through the tissue to be treated and thereby secure the implant device to the tissue to be treated, (5) at least two electric poles located along the elongated body or the attachment mechanism so that, when the attachment mechanism is folded back and attached to the elongated body, the two or more electric poles can provide electrostimulation or electrical monitoring to the tissue within the loop, and (6) an electrical connection terminal at the proximal end for connection to a power source wherein the two or more electric poles are electrically connected to electrical connection terminal.
Still another object of the invention is to provide an implant device which, once anchored in the tissue or viscera to be treated, is capable of reducing to a minimum its excessive length inside the abdomen. Another object of the invention is to provide an implant device that effectively protects the electrical connection terminals that connects to a power source so as to be able to perform the implantation in a dry arena, thereby permitting the entire procedure, including anesthesia, to be carried out in an extremely short time.
These and other features and advantages of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description, including the drawings.